Axle and method of forming same



Oct. 11, 1938. J. H. GETTIG 2,133,091

AXLE AND METHOD OF FORMING SAME Filed Oct. '7, 1936 IIIIIIIIIII 'IIIIII/fa 2 E Patented Oct. 11, 1938 AXLE AND METHOD OF FORMING SAltIE JosephH. Gettig, Buchanan, Mich., assignor to lark Equipment Company,Buchanan, Mich., a corporation of Michigan Application October '7,

4 Claims.

This invention relates to axles, and more particularly is directed tothe construction of axles for use in trailers and the like where nodriving means is provided but the wheel is journaled for rotationdirectly on the axle.

It has heretofore been the practice to-construct such axles from solidstructural members, or from hollow members having theends coined orsuitably forged to produce the bearing seats for the hub of the wheel.

The present invention proposes to form the axle from a piece of tubingsuch as a seamless tube or a tube formed by rolling up and welding aflat sheet of stock, and contemplates especially the 1 formation of theaxle ends in such manner as to prevent defects such as cracking,fractures or the like which have been one of the main disadvantages ofaxles previously produced.

One object of the present invention is to provide for reduction of theends of the tubular axle member in such manner as to prevent any folds,cracking or faulting of the end section of the axle so that a section ofuniform strength and rigidity is produced.

Another object of the present invention is to provide for inserting amandrel or centering member within the end of the axle tube afterinitial reduction and prior to its being swaged to complete form wherebythe internal surface of the axle end embraces this mandrel-like memberupon completion of the swaging operation.

Other objects and advantages of the present invention will appear morefully from the following detailed description which, taken in con- 35junction with the accompanying drawing, will disclose to those skilledin the art the particular method of forming the axle constituting thepresent invention.

In the drawing:

Figure 1 is a sectional view through the axle blank prior to theformation of the axle;

Figure 2 shows the first step in the forming operation, being partly insection;

Figure 3 is a corresponding view illustrating the axle after the secondoperation on the blank;

Figure 4 is a corresponding view showing the finished axle; and

Figure 5 is an end section view showing the defects occurring in priormethods of forming this type of an axle.

Referring now in detail to the drawing, the blank 5 of Figure 1 may be aseamless tube, or may be a piece of flat stock rolled into tubular formand then longitudinally welded along the abutting edges. The blank 5preferably has an 1936, Serial No. 104,428

initial wall thickness as indicated by the wall 8, and is of a lengthslightly less than the desired length of the finished axle.

The first step in forming the axle of the present invention is to reducethe end sections theremade.

Simultaneously with this reduction the end portion of the axle isincreased in wall thickness and elongated.

- After the reduction is effected at opposite ends of the housing, andbefore the ends are completely closed, a rod or mandrel-like member 8 isinserted into each end of the axle, and is held in centered positiontherein in any suitable manner.

The rod 8 may be of steel, iron, or any equivalent material, butpreferably should be of relatively cheap material inasmuch as it servesno purpose so far as load support or wear is concerned.

After the rod has been placed in position, each end of the axle issubjected to further reduction while the rod 8 remains in place.

As the swaging is completed, the thickened reinforced end 8 of the axleencloses and completely embraces the rod 8, holding the same in fixedposition and also thereby preventing any folding, lapping or cracking ofthe axle or shaft.

Such defects are undesirable and may be of serious nature, especially ifthe axle is to be heat treated.

The swaging operations for reducing the diameter of the axle ends may beaccomplished by endwise swaging which, in turn, will produce slightelongation of the axle so that the finished axle will be of the requiredlength, it being re membered that the blank is slightly shorter than theaxle length required to accommodate this elongation. As shown in Figure4, the reduced end portion 8 of the axle which encloses and embraces therod 8 is joined by the frusto-conical portion II! to the rear portion 1of the initially reduced cylindrical end of the axle. The swagingoperation also produces a considerable thickening of the walls of theaxle at the same time that elongation is produced, thus providing athickened reinforced end for the axle which is then subsequentlymachined on the surfaces 1 the wheel hub.

The provision of the rod 8 in the end of the axle prevents the formationof fissures, cracks or folding within the end of the axle as isindicated in Figure at l2, where such defects are formed due to the factthat the axle is reduced to produce a solid end and consequently, theinternal surface of the end of the blank is folded and lapped duringthis reduction, producing the fissures which are especially undesirableif the axle is to be subsequently heat treated.

It will therefore be apparent that I have provided a novel process forforming what is known as a dead type of axle in which the wheels aremounted for free rotation at opposite ends of the axle on bearing seatsformed by the reduction of these ends, with the consequent thickening ofthe walls thereof.

I do not intend to be limited to the exact details shown and describedin connection with the illustrated embodiment of the present invention,as the particular process employed may equally well be employed forother types of shafting for uses other than as axles or the like. Theinvention is therefore to be limited only as defined by the scope andspirit of the appended claims.

I claim:

1. The method of forming an axle from a tubular blank which comprisesinitially reducing the opposite ends of the blank to form end portionsof hollow cylindrical section and of increased wall thickness and havingfrusto-conical portions between said ends and the remainder of theblank, inserting solid mandrel-like members in the reduced ends of saidblank, subsequently reswaging said frusto-conical section to form anintermediate cylindrical bearing seat spaced from said first reducedportion by a frusto-conical section with said first reduced portionbeing further reduced in such manner as to rigidly embrace and enclosesaid member to thereby close the end of the axle xially.

2. An axle comprising a tubular blank having reduced thickened endportions rigidly embracing solid mandrel-like members closing theinterior of said axle and having external bearing seat portions ofdifferent diameters spaced axially by a frusto-conical section at eachof the reduced ends thereof, said members preventing fracturing of theinternal portions of said ends.

3. In the manufacture of a dead axle from a tubular blank, the method offorming the axle end which comprises initially reducing the end of saidblank to form a thickened portion joined to the remainder of the blankby a frusto-conical section, inserting a solid cylindrical mandrel ofsmaller diameter than the internal diameter of said reduced end intosaid end with the inner end of said mandrel adjacent saidfrusto-conicalsection, and reswaging a substantial portion of, saidreduced end to engage about and lock said mandrel therein, and toproduce a second frusto-conical section intermediate said reswagedportion and the remaining length of said initially swaged portion. r

4. In the manufacture of axles from tubular blanks, the method ofproducing a solid end free from fissures and cracks and capable ofrotatably supporting a wheel thereon which comprises initially swagingthe end of said blank to reduce its-diameter and increase its wallthickness, inserting a solid mandrel into said end, and reswaging amajor portion of said end to flow the interior surface thereof intogripping engagement with said mandrel, and to form annular bearing seatportions of different diameters separated by a frusto-conical section,said mandrel preventing collapse'of the internal surface of said endduring-said reswaging whereby folding or cracking of said surface isprevented.

JOSEPH H. GETTIG.

